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Year : 2014  |  Volume : 2  |  Issue : 4  |  Page : 99-103

Prevalence of Hypertension and Assessment of "Rule of Halves" in Rural Population of Basavanapura Village, Nanjangud Taluk, South India

MBBS student under Department of Community Medicine, JSS Medical College, JSS University, Mysore, Karnataka, India

Date of Web Publication10-Dec-2014

Correspondence Address:
Jatin Venugopal Kutnikar
#1046, HIG 2nd Stage, Bogadi North, Mysore - 570 026, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2321-449X.146609

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Context: World Health Day is celebrated on 7 th April to mark the anniversary of the founding of World Health Organization in 1948. Each year a theme is selected for World Health Day that highlights a priority area of public health concern in the world. The theme for 2013 is on high blood pressure (BP). High BP, if left uncontrolled increases the risk of heart attacks, strokes, and kidney failure. Materials and Methods: A community-based cross-sectional survey was carried out among adults (>18 years) in Basavanapura Village, Nanjangud Taluk using simple random sampling method to study the pattern of BP using the Seventh Report of the Joint National Committee criteria. A total of 447 persons were screened. A total of 223 individuals (90 men and 133 women) were selected by simple random sampling, interviewed, and clinically examined for hypertension. BP of all the study participants was measured using a standardized technique. Statistical Analysis Used: Mean ± standard deviation (continuous data), proportions and percentages (categorical data), Chi-square test (association between age and hypertension) and odds were calculated to see in which age group the risk of hypertension was more. Kruskal-Wallis test was used to test the significant difference of systolic BP and diastolic BP for males and females among age groups. Results: Of the 447 persons surveyed in Basavanpura Village, BP was recorded among 223 individuals. The overall prevalence of hypertension was found to be 36 (16.1%), of which 22 (61.1%) were diagnosed, 20 (90.90%) treated, and only 14 (70.0%) controlled. Increasing age, sedentary lifestyles, and male sex were identified as the predisposing factors. Conclusions: The prevalence of hypertension in the village is slightly higher (16.14%) than the national prevalence (14%). There is an urgent need to educate the people to modify the lifestyle and to monitor their BP values regularly.

Keywords: Basavanapura, blood pressure, hypertension, prevalence, "rule of halves", rural Mysore

How to cite this article:
Kutnikar JV, Basavegowda M, Kokkada V, Ashok NC. Prevalence of Hypertension and Assessment of "Rule of Halves" in Rural Population of Basavanapura Village, Nanjangud Taluk, South India. Heart India 2014;2:99-103

How to cite this URL:
Kutnikar JV, Basavegowda M, Kokkada V, Ashok NC. Prevalence of Hypertension and Assessment of "Rule of Halves" in Rural Population of Basavanapura Village, Nanjangud Taluk, South India. Heart India [serial online] 2014 [cited 2023 May 31];2:99-103. Available from: https://www.heartindia.net/text.asp?2014/2/4/99/146609

  Introduction Top

Blood pressure (BP) is the force exerted on artery walls as the heart pumps blood through the body. Hypertension, or high BP, occurs when BP is constantly higher than the pressure needed to carry blood through the body. [1] Hypertension often goes unnoticed and can cause damage to the heart and blood vessels which, if untreated, can lead to stroke or heart attack. Hypertension is responsible for significant premature mortality, reduced quality of life and significant costs to the health and social care system and to the economy. [2]

Hypertension, physical inactivity, increased level of blood lipids, obesity, and faulty dietary habits are the primary risk factors for cardiovascular morbidity. [3]

The prevalence of hypertension ranges from 20% to 40% in urban adults and ranges from 12% to 17% in rural adults. The number of people with hypertension is projected to increase from 118 million in 2000 to 214 million in 2025, with nearly equal numbers of men and women. [4]

Basavanapura a village located in Nanjangud Taluk represents a scenario wherein, in spite of its location in close proximity to the town and city, yet has not caught up with the urbanization. The population here represents an ethno-culturally homogeneous population for studies on patterns of hypertension in a rural population. The modern day stress and strain and changing lifestyles pose a risk to the development of hypertension not only in the obese and the old, but increasing trends in the lower age groups and the nonobese individuals.

The "rule of halves" in hypertension states that "half the hypertensive patients are not known to health services (i.e., remain undiagnosed), half of those with known hypertension avail/receive no treatment and half of those treated, do not achieve adequate control". [5] In this study, an attempt was made to assess the applicability of this rule to the rural population in south Karnataka.

  Materials and Methods Top

Basavanapura was chosen for the study as it was part of the Family and Health Advisory Survey in MBBS phase 2 curriculum in the Department of Community Medicine, JSS Medical College, located in Nanjangud Taluk, Mysore district (Karnataka), the village Basavanapura (Code: 2864700) [6] has an area of 138 hectares.

A household list was made after a demographic survey of the entire village. Individuals were selected by random sampling based on the age group. A community-based cross-sectional survey was carried out among adults above 18 years in Basavanapura Village, Nanjangud Taluk using simple random sampling method to study the pattern of BP using the Seventh Report of the Joint National Committee (JNC-VII) criteria. Pregnant women, severely ill and bedridden elderly people were excluded from the survey. A total of 447 persons were screened out of which a total of 223 individuals (90 men and 133 women) were interviewed and examined.

Measurement of blood pressure

The BP was measured by two MBBS phase 2 students using a mercury column sphygmomanometer by a standardized technique in the sitting posture after the subject had rested for at least 15 min. It was recorded in the right arm using a cuff of standard size with the instrument at the level of the subject's heart. Two readings were taken at intervals of 10-15 min for each subject. Participants, who had eaten, smoked or consumed alcohol was made to rest for 1 h before recording the BP. Whenever a high BP was recorded, the reading was rechecked on the next day in the same manner.

Definitions and diagnostic criteria

Diagnosis of hypertension was made in all subjects who reported to be known hypertensives and were under antihypertensive medication and/or had systolic blood pressure (SBP) of 140 mmHg or greater and/or diastolic blood pressure (DBP) of 90 mmHg or greater. [7] Controlled hypertension was defined as those who were on treatment and had a BP of <140/90 mmHg.

Statistical analysis

All data were entered on Microsoft Excel. Continuous data are expressed as mean ± standard deviation and categorical data are expressed as proportions and percentages. Chi-square test was used to find the association between age and hypertension and odds are calculated to see in which age group the risk of hypertension is more. For testing the significant difference of SBP and DBP for males as well as females among age groups, we used Kruskal-Wallis test because normality was questionable, and sample sizes within each group are small, while effect sizes are calculated for multiple comparisons. A two-tailed P < 0.05 was considered as significant. Statistical analyses were performed using IBM® SPSS STATISTICS STANDARD -Version 21 (for Microsoft® Windows 7).

  Results Top

Blood pressure was recorded in 90 men and 133 women. Mean age for men was 44.27 ± 16.54 years and for women was 41.92 ± 16.72 years [Table 1].
Table 1: Mean age distribution of sample population

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Blood pressure levels

[Table 2]a presents the distribution of SBP for men and women by their age and sex. The mean SBP in men was 125.49 (±10.03) mmHg and in women it was 124.52 (±13.82) mmHg. The mean SBP increased with age and were highest in the age group ≥60 years in both genders (SBP: 131.64 [±14.02] mmHg in men and 136.45 [±17.71] mmHg in females). The Kruskal-Wallis test for comparison of age groups indicates that there is statistically significant difference in the distribution of SBP in men among the age groups, χ2 (5) = 13.890; P = 0.016. When calculating the effect size for the pairs of groups where significant difference found we observed that by adding the age group 51-60 to any other age groups inflates the effect size. So that the age group 51-60 is statistically significantly different from the other age groups. Meanwhile, there is no statistically significant difference in SBP for women among the age groups (χ2 (5) = 3.730; P = 0.589).
Table 2

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[Table 2]b presents the distribution of DBP for men and women by their age and sex. The mean DBP in men was 81.24 (±6.60) mmHg and in women it was 79.46 (±9.15) mmHg. The recorded mean DBP however was highest in the age group 51-60 years (DBP: 83.94 [±5.69] mmHg in males and 84.20 [±9.95] mmHg in females). The Kruskal-Wallis test for comparisons of age groups of men and women indicates that there is no statistically significant difference in the distribution of DBP among the groups (χ2 (5) = 6.615 and P = 0.251 for men and χ2 (5) = 0.425 and P = 0.995 for women).

Prevalence of hypertension

The prevalence of hypertension was 16.14% with 36 subjects being hypertensives out of 223 study subjects. Of 36 hypertensive persons, 22 (61.1%) had been previously diagnosed to be hypertensive. There were more women-21 (58.3%) with hypertension than men-15 (41.7%). There was a significant increase in the prevalence of hypertension with increasing age in both genders. The maximum prevalence of hypertension was in the age group >60 years for women (34.61%) and age group 51-60 years for men (40.0%). According to the JNC-VII classification of the stages of hypertension, the percentage of women hypertensives in stages 1 and 2 were more than the males.

The prevalence of hypertension increased significantly with increasing age (χ2 (5) =15.866; P = 0.007). While there were no cases detected in the age group 18-20 years, the lowest prevalence was found in the age group 21-30 years (11.1%) and was highest in the age group above >60 years (30.6%). The odds are the expected number of hypertensives per nonhypertensives, so the age group ">60" with the largest odds is most likely to suffer from hypertension [Table 3].
Table 3: Odds of hypertension across age groups

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Awareness, treatment, and control of hypertension

Only 61.1% (22) of hypertensive subjects (36) had been previously diagnosed and of them 90.9% (20) were on treatment. The BP was adequately controlled in only 70.0 (14) of these subjects [Table 4], [Figure 1].
Table 4: Assessment for applicability with "rule of halves"

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Figure 1: Assessment of "rule of halves" in hypertension

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Pattern of hypertension (Seventh Report of the Joint National Committee criteria)

The BP recordings reveal that 16.14% (36) of the sample population were normotensives (M:F = 11:25), 67.7% were pre-hypertensives (M:F = 64:87), 12.1% were stage 1 hypertensives (M:F = 13:14) and 4.0% were stage 2 hypertensives (M:F = 2:7) at the time of recording (note: These numbers also include the hypertensive patients under treatment and with controlled BP, in which case, they have been categorized according to the BP at the time of recording using JNC-VII criteria) [Table 5].
Table 5: Categorization of subjects according to the JNC-VII criteria

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  Discussion Top

Our results reveal the prevalence of hypertension in Basavanapura to be higher than the national average in rural India (14%). [8] Rates of hypertension were higher in females than in males as opposed to the recent studies from India and other developing countries. [9],[10],[11] Social stress, underlying environmental and hereditary factors may predispose to hypertension in women.

Among the subjects, a striking 67.71% (151) came under the prehypertension category (JNC-VII guidelines). Studies show patients with prehypertension are at increased risk of progression to hypertension; those in the 130-139/80-89 mmHg BP range are at twice the risk to develop hypertension than those with lower values. [12]

It is interesting to note that Basavanapura is located just 1 km from the nearest Taluka hospital at Nanjangud. In spite of its close proximity, we noticed a reluctance to visit the hospital for consultation and treatment for the ailments by the population. Lack of transport (the village is located across the river Kabini) was cited as the main reason behind this apart from the notion of poor health care at the government set up.

The relationship between BP and risk of cardiovascular disease (CVD) events is continuous, consistent, and independent of other risk factors. The higher the BP, the greater is the chance of heart attack, heart failure, stroke, and kidney disease. For individuals 40-70 years of age, each increment of 20 mmHg in SBP or 10 mmHg in DBP doubles the risk of CVD across the entire BP range from 115/75 to 185/115 mmHg. [13] Physical activity and hypertension data from this study shows that it is in line with the trends.

There are a number of limitations of this study. Those who did not have their BP checked are more likely to be male and belonging to the economically productive age group. Although this may have resulted in some bias, we have sufficient representation in this age group to make it statistically significant. We are unable to report on the physical exercise status of the survey population and its effect on hypertension rates, although the higher levels of obesity seen in females may be a useful proxy for physical exercise and indicate higher levels of physical activity in males. The data on occupation is a general outline for the assessment of physical exercise although not very conclusive.

In the study sample, 61.1% of those with hypertension were aware of their disease and most (90.9%) were on treatment. However, 70.0% of them the BP was adequately controlled (SBP <140 mmHg and DBP <90 mmHg). Thus, there is a need to effectively combat the burden of hypertension in this population of Basavanapura. Education about lifestyle modification and awareness and adherence to treatment is to be carried out on a large scale and in a systematic manner in rural areas also.

  References Top

Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003;42:1206-52.  Back to cited text no. 1
Department of Health and Children. Changing Cardiovascular Health: National Cardiovascular Health Strategy 2010-2019. Dublin: Department of Health and Children; 2010. Available from: http://www.dohc.ie/publications/changing_cardiovascular_health.html. [Last accessed on 2013 Feb 11].  Back to cited text no. 2
Shapo L, Pomerleau J, McKee M. Epidemiology of hypertension and associated cardiovascular risk factors in a country in transition: A population based survey in Tirana City, Albania. J Epidemiol Community Health 2003;57:734-9.  Back to cited text no. 3
Reddy KS. Regional case studies - India. Nestle Nutr Workshop Ser Pediatr Program 2009;63:15-24.  Back to cited text no. 4
Smith WC, Lee AJ, Crombie IK, Tunstall-Pedoe H. Control of blood pressure in Scotland: The rule of halves. BMJ 1990;300:981-3.  Back to cited text no. 5
Govt. of India, Ministry of Home Affairs: Census of India 2001. Available from: http://www.censusindia.gov.in/2011-common/census_data_2001.html. [Last accessed on 2013 Feb 09].  Back to cited text no. 6
Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo Jr. JL, Jones DW, Materson BJ, Oparil S, Wright Jr. JT, Roccella EJ.- The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). Vol. 42. American Heart Association;2003. p. 1206.  Back to cited text no. 7
Yajnik CS. The lifecycle effects of nutrition and body size on adult adiposity, diabetes and cardiovascular disease. Obes Rev 2002;3:217-24.  Back to cited text no. 8
Olatunbosun ST, Kaufman JS, Cooper RS, Bella AF. Hypertension in a black population: Prevalence and biosocial determinants of high blood pressure in a group of urban Nigerians. J Hum Hypertens 2000;14:249-57.  Back to cited text no. 9
Dwivedi S, Singh G, Agarwal MP. Profile of hypertension in elderly subjects. J Assoc Physicians India 2000;48:1047-9.  Back to cited text no. 10
Agarwal AK, Yunus M, Khan A, Ahmad J. A clinical-epidemiological study of hypertension in rural population of Jawan Block, Distt, Aligarh (UP) India. J R Soc Health 1994;114:17-9.  Back to cited text no. 11
Vasan RS, Larson MG, Leip EP, Kannel WB, Levy D. Assessment of frequency of progression to hypertension in non-hypertensive participants in the Framingham Heart Study: A cohort study. Lancet 2001;358:1682-6.  Back to cited text no. 12
Lewington S, Clarke R, Qizilbash N, Peto R, Collins R, Prospective Studies Collaboration. Age-specific relevance of usual blood pressure to vascular mortality: A meta-analysis of individual data for one million adults in 61 prospective studies. Lancet 2002;360:1903-13.  Back to cited text no. 13


  [Figure 1]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]


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